Video display system

ABSTRACT

A display system that uses a digital storage and processor having stored therein a plurality of sources of binary coded information representative of a plurality of display messages and patterns. A graphic generator converts coded information into analog stroke or painted display information. This stroke information and/or asynchronous display information from other sources is converted into television raster information which is then cyclically stored on a magnetic disk, together with displays from other synchronous noncoded and coded sources as well as live television. A plurality of remote stations can select any display information which is converted as necessary to raster video information. These frames may be recorded on one or more tracks of the magnetic disk. This information is then applied to the television monitor at the station. The operator at the station can then control the processing of the binary coded information and request other display material while viewing the monitor and in addition, can correlate portions of images on the CRT display with the originating digitally controlled stroke information. Furthermore, raster information of several selected tracks as well as synchronized video from other sources can be compared and/or mixed.

United States Patent [191 Brown et al.

[4 1 Jan. 15, 1974 VIDEO DISPLAY SYSTEM [75] Inventors: Carol] J. Brown,San Jose; Donald J. Primary Examiner-Dung" Trafton Chesarek, Los Gatos;Dale E. Fisk, Attorney-Thowas y San Jose; Joseph T. Ma, Los Gatos, allof Calif; Harold F. Martin, 57 ABSTRACT Chappaqua, N.Y.; Zack D. IReynolds San Jose, C lif A display system that uses a digital storageand processor having stored therein a plurality of sources of [73]Asslgnee: lmematlfnal Busmess Machmes binary coded informationrepresentative of a plurality Corporatlon, Armonk of display messagesand patterns. A graphic generator [221 Filed; June 18, 1971 convertscoded information into analog stroke or painted display information.This stroke information [21] PP N05 154,581 and/or asynchronousdisplayinformation from other I Related s Application Data sources is convertedinto television raster information 63] Continuamm of Ser No 782 154 Dec9 1968 which is then cyclically stored on a magnetic disk, toabandoned.I gether with displays from other synchronous noncov ded and codedsources as well as live television. A plu- [52] Us. CL 340/324 AD,178/66 A rig/DIG. 37 rality of remote stations can select any displayinfor 5 1] Int. Cl. .J. G06f 3/14 which is Converted as necessary rasterVida) 581 Field of Search 178/6.6 A DIG. 33 informatim- These frames maybe rewded One ml 178 MG 346/324 more tracks of the magnetic disk. Thisinformation is then applied to the television monitor at the station.[56] References Cited The operator at the station can then control theprocessing of the binary coded information and request UNITED STATESPATENTS other display material while viewing the monitor and 2,594,7314/1952 Connolly 340/324 AD in addition can correlate portions of imageson h gffi 1 33%;: CRT display with the originating digitally controlled3387084 6/1968 g"; [78/6 8 stroke information. Furthermore, rasterinformation of 3 394 366 7/1968 Dye .Ilium..-.IIIT340 324 a Severalselected tracks as as Synchronized Video 3:485:946 12/1969 Jackson etal. l78/6.6 A x from other Sources can be Compared and/0r mixed-3,539,7l5 11/1970 Lemelson l78/6.6 A X l D 3,546,377 12/1970 Troll178/DIG437 x 5 C 4 Flgures vlllro TAPE v I: 1 RECORD 1''' :1 451 150 lno 51 w SCAN L GRAPHC [CONVERTER 4 DISTRIBUTION 1 mm GENERATOR SELECTORl l l T l SCAN CONVERTER BINARY l 52 GENERATOR DIGITAL m 2 00m STORAGEDISPLAY" g H E 74 l l k BINARY conrl l DISPLAY N HULTIPLEX 450 PROCESSORMEANS {20 l f F L illa sullslslnl COIPARE oou rol I ii isoeolsoleollolso PATENT {gm 1 5 w;

SHEET 2 OF 2 Q5016 ZQSEEQ $85 25m; Q72 323:6:

. l 7 VIDEO DISPLAY SYSTEM PRIORITY The present invention is acontinuation of my copending application Ser. No. 782,154 now abandoned,filed Dec. 9, 1968, and assigned to the same assignee as thisapplication.

BACKGROUND OF THE INVENTION 1. FIELD OF INVENTION A display systemwherein the displays originate from a digital processor storage unit andother sources.

2. DESCRIPTION OF THE PRIOR ART In computer display systems,binary-coded information is stored which represents a particular messageor pattern to be displayed on a cathode ray tube. This binaryinformation is decoded into a form suitable to be applied to the displaydevice such as an analog signal to deflect an electron beam in a stroketype movement of an electron beam. In order to regenerate the display,the predetermined information is cyclically accessed and repeatedlyapplied to the display. A plurality of displays are frequently employedwhich have access by some remote means to the processor.

The prior art display signals normally only emanate from one source,that is, a computer or photographic slides or a tape recorder, etc.,since normally it is not feasible to accommodate other sources.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide a new and improved display system having a central processingunit which can originate and modify displayed information.

A further object of the invention is the provision of a new displaysystem for selectively applying image forming signals to a displaydevice wherein the digital display information in the computer or filescan be processed and changed without affecting the visual image.

A still further object of the invention is to provide a new and improveddisplay system that has a high degree of flexibility, and canaccommodate various sources of displayable information.

Still another object of this invention is the provision of a new andimproved display system that can utilize various sources of visualdisplays with a minimum of complexity at the display station(s). v

. Still a further object of the invention is to provide a display systemthat can identify a point or area on the display with a minimum ofinterruption and/or computer processing time.

The above objects of the present invention are realized in one formthereof by employing a computer based system which contains a pluralityof storage locations having binary information representative of aplurality of displayable frames of messages or patterns. This coded datais selectively converted to television raster information which is thenbuffered and regenerated in this noncoded formfThis noncoded informationis cyclically regenerated to thereby provide a visually continuousdisplay on a monitor. By cyclically regenerating the noncodedinformation, the binary coded information in the computer representingthis display can be processed, modified, compared, etc., withoutaffecting the visual display at the remote station- As a further featureof the invention, a means is provided at the remote station to generateXY information of a particular point on the display. This information iscompared with signals corresponding to spatial coordinates which areprovided at the output of a graphic generator prior to scan conversioninto raster video form. In so doing, process time of the computerprocessor is saved, and display signal regeneration is not interrupted.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 contains a schematic diagrampartially in block form of a display system embodying the invention,

FIG. 2 illustrates a graphic generator together witha scan convertersuitable for use in the embodiment in FIG. 1,

FIG. 3 illustrates an electron beam deflection path, and

FIG. 4 illustrates a block diagram of a system suitable as a coordinatecompare.

GENERAL DESCRIPTION The above objects of the present invention areaccomplished by a system connected'to a digital storage and processor 10that has a plurality of storage locations containing binary codedinformation, representing a plurality of separate images. Control means20 can be actuated by keyboard 100 or other suitable means to effectmovement of the data for an image to a graphic generator 30 whichtransduces the binary coded information into X, Y and Z signals whichare capable of deflecting 'an electron beam to thereby provide a stroketype display or pattern. This X, Y, Z information is selectively appliedto an electron beam type scan converter 40 or 50 which converts the X,Y, Z display information into television type full frame formattedraster video information which can be a time sequence of analog ordigital signals. The output of the scan converter is applied to a trackselector 60 which then switches this video information to a magneticdisk storage having a plurality of endless tracks thereon. Tracks of themagnetic storage unit 70 are read out through a distribution network toprovide raster displays by a plurality of remote television monitorssuch as 90. Also, at the remote station and positioned adjacent to thetelevision monitor is a coordinate identification means which identifiesXY locations of selected portions of the displayed image provided bymonitor 90. Other sources of images such as from films or real scenescome from a scanner or television camera 150, a video file or taperecorder 160, or a television camera 170.

When the signals are provided in noncoded video form (such as analog)from the storage disk 70, they are regenerated and produce a continuousvisual display on the monitor such as 90. The computer-derived.

display source is also simultaneously present in coded form in thedigital storage and processor 10. Thus,

while the image is being regenerated and viewed in noncoded form, theimage in coded form can be scanned and utilized or processed in thedigital processor 10. The coded image can be analyzed, compared,modified, etc., while the displayed noncoded image is being viewedwithout interruption. In addition, without interrupting this viewing,the image in noncoded video form can also be compared and/or coordinatedwith other images on the disk.

The magnetic disk storage 70 includes a clock track having clock pulsesthereon which develop horizontal and vertical raster sync. Since thebinary coded information is not being regenerated to provide aregenerative display and since the readout of the scan converter issynchronized with the sync signals from the storage disk, the scanconverters 40 and 50 can then be used, without interrupting the display,to convert exterior asynchronous display information to synchronousdisplay information. Synchronous exterior video sources can also beapplied to the monitors or records on the disk in response to thesynchronizing pulses developed from the clock pulses on the disk. Theclock track can have conventional vertical and horizontal televisionsync pulses applied thereto for two video fields so that when using aconventional monitor synchronization for 525 lines is provided. Thereadout of the scan converters 40 and 50 is synchronized with the clockpulses or sync pulses on the clock track.

DETAILED DESCRIPTION The digital storage and processor includes aplurality of frame storage locations ll, 12 and 13, each of whichcontains binary coded information representing a message and/or patternsfor an individual image shown as number 1, number 2 and number N, respectively. As illustrated, the binary coded information is a series ofbinary words with each word representing a letter or numeral by way ofan alphanumeric code. In these codes, such as used with the IBM 2250display, normally the words consist of six to eight binary bits. Whenthis information is applied to a conventional graphic generator 30, theoutput thereof will be analog X and Y signals (horizontal and verticalelectron beam deflection signals) as well as a Z signal (analog ordigital beam gating signal).

In addition, the storage locations ll, 12 and 13 could contain imagesother than alphanumeric. In such a case, binary coded words mayrepresent end points of lines. These end points would then be convertedto X and Y (horizontal and vertical) analog deflection signals thatwould deflect the electron beams from one end point to another as wellas Z or beam gating signals to enable proper intensification of thebeam. Other suitable generators that convert binary coded information(of images) to displays are shown in U.S. Pat. Nos. 3,334,304 and3,205,488. Also see January 1961 Proceedings of IRE, pp. 185-195.

The operator at station S can effect, by way of keyboard 100, commandsfrom the subsystem control to selectively transmit the binaryinformation for one image from location 11, 12, etc. to a graphicgenerator 30.

The graphic generator 30 converts the binary-coded information to analogX and Y deflection and Z gating or intensification information that issuitable to deflect an electron beam in a stroke type form such as iscommon in graphic displays and, as illustrated in FIG. 3, (whichprovides an electron beam path of the number seven by moving the beamfrom A to B). This stroke type deflection is converted to televisionraster type information by applying it to either a scan converter 40 ora scan converter 50.

FIG. 2, for purposes of clarity, sets forth in more detail aconventional type graphic generator such as is employed to convertbinary coded display information into alphanumeric stroke information.THe graphic generator 30, so illustrated, continuously has digital Xposition information which is applied to a coarse D to A converter 31and Y position information which applies to a coarse D to A converter32. The output of converter 31 is applied to an amplifier or yoke driver33 and the output of converter 32 is applied to an amplifier or yokedriver 34. Conventionally, the coarse X information provides a signalrepresenting the distance from the sides of the display at which acharacter starts to be written and the Y information indicates how farfrom the bottom or the top of the display (which line) the start of thecharacter writing begins. Fine information is provided to a charactergenerator 35 which converts this binary coded information into fine Xand Y information analog and Z information which could be digital oranalog. Thus, if the binary fine information from the processorindicates an A to be written, the character generator provides theanalog deflection signal for the X and Y deflection yokes, necessary towrite an A at or from the point determined by the X and Y coarseinformation. The X fine analog signal is amplified by amplifier 37 andcombined with the coarse analog signal at point C. The Y fine analogdeflection sig nal is combined with the coarse analog deflection signalat point D. Character generator 35 furthermore generates an intensitysignal which passes through the intensity amplifier 36 to vary thecurrent of the electron beam by varying the bias on a grid 41. If thedisplay is to be digital this signal will merely-turn the electron beamon and off as is known conventionally.

The typical scan converters 40 and 50 which are illustrated herein maybe a type of electron beam storage tube such as a television camera orvidicon tube described in more detail in co-pending application, Ser.No. 775,861, filed Nov. 14, 1968 in the name of John W. Brookman, JohmB. Murphy, Zack D. Reynolds and entitled Photo Erasable Scan Converterand assigned to the same assignee as the present invention. Thiscopending application describes a television camera tube in which anelectron beam is applied to the target in a stroke fashion and then thetarget is read out in raster form by the electron beam. Any suitablescan converter, such as a storage tube, could be employed for thefunction defined herein. For the purposes of illustration, the storagetube 40 includes a cathode 47, a grid 41 which could gate on or off theelectron beam or vary the intensity of the beam by the output of the Zintensity amplifier 36. The coarse and fine X deflection signal combinedat point C is applied to the X deflection yoke 42. The fine and coarse Ydeflection signal combined at point D is applied to the Y deflectionyoke 43. During write, switches 46a and 461; are up.

Thus, the binary coded information defining one image is converted bygenerator 30 to electron beam analog stroke information to provide animage on target 44. During readout, switches 46a and 46!) are down andthe yokes 42 and 43 are deflected in the conventional raster mode bydeflection circuits 46 so that the target 44 develops at the output 45 atypical raster or television type signal. The output of the scanconverter 40 or 50 is selectively applied to a cyclic storage means suchas a magnetic disk by way ofa channel selector 60.

The track selector 60 selectively applies the raster information fromeither scan converter 40 or 50 to one of the plurality of magnetictracks TRl through TRN by way of magnetic heads 71 through 71N. Themagnetic disk 72 is rotated at 1,800 rpm so that each rotation of thedisk takes the time normally used or elapsed for the recording orplaying back of onevideo frame (two interlaced video fields). The diskcan be rotated at 3,600 rpm so that the time for one rotation of thedisk is equal to the time required for one video field. In such a case,two tracks would have to be utilized to provide one video frame byalternately switching between these tracks.

A separate track TRC is employed on the disk 72 with this trackcontaining vertical and horizontal synchronizing pulses required for onevideo frame. In a conventional television system, this would require 525horizontal sync pulses and two vertical sync pulses. The signal on thetrack TRC is either the required number of the sync pulses, horizontaland vertical (for one frame) or conventionally a multiple of pulses arerecorded with the frequency divided down by a sync generator 74 toprovide the required number of vertical and horizontal sync pulses.

When the actual horizontal and vertical sync pulses are recorded, thesync generator 74 is not needed but rather the output of head 73 isconnected directly to the circuits 46 of scan converters 40 and 50 so asto provide proper synchronization of the horizontal and vertical rastercircuits 46 shown in FIG. 2. In addition, the head 73 would alsobedirectly connected to the distribution network 80 where the sync signalswill be added to the video information from any of the tracks TRlthrough 'IRN. Alternatively, two tracks may be employed for thesynchronization function of TRC, one with horizontal sync pulses and onewith vertical sync pulses. Sync vpulses are made available for othersources 150, I60 and 170 to provide a synchronous input directly intothe track selector 60. Alternatively, the clock track TRC could containa multiple number of clock pulses which, when divided down, will produce525 horizontal sync pulses and twover'tical sync pulses. This divisionoccurs in the sync generator 74 and operates in the same fashion as isdone for developing sync pulses for a conventional television camera. Anexample would be that the clock track contained 6,300 pulses with thisoutput being divided by 12 to produce 525 horizontal pulses and dividedby 3,150 to produce two vertical sync pulses. The magnetic head 73 isemployed to record these pulses and thereafter reads these pulses out(when appropriate) to a sync generator 74 which divides the frequency ofthe pulses down to provide both the horizontal and verticalsynchronization pulses.

Recording a different number of pulses on TRC and dividing by differentnumbers in the sync generator 74 will allow television displays havingother than 525 lines to be generated. This could be down to generatedisplays compatible with 873 line closed-circuit television monitors,for example.

It will be understood that the video information applied to the tracksTRl through TRN could be applied on a carrier such as an FM carrier andthen recorded on disk 72. Such a suitable selector 60 and FM recordingis illustrated in co-pending application Ser. No. 682,432 filed Nov. 13,1967 in the name of J. L. Adkisson and A. B. Manildi. On readout, an FMdemodulator is used to drive the video signal.

The heads 71 through 71N are always connected to a distribution network.In so doing, the video information is applied through the network 80 toa monitor such as 90, even during writing or recording so as to providea non-interrupted display drive. A display selection can be accomplishedby way of the keyboard terminal 100 which is connected to the subsystemcon- 5 trol to thereby command the readout of one of the storagelocations 11 through 13 to the graphic generator 30, or to select analternative input such as I50, 160 or 170.

Since the magnetic disk storage 70 regenerates to produce a continuousdisplay on the monitors such as 90, other auxiliary displays can moreeasily be provided in the system such as photographic file 151 which canbe picked up by a scanner or TV camera 150. Furthermore, a TV camera 170can provide live information for displays. Both 150 and 170 can beconnected to a video file or tape recorder 160 or alternately to one ofthe scan converters 40 or 50 in asynchronous mode; in a synchronousmode, they may be connected directly to channel selector 60, thence todisk storage 70, and directly to distribution 80 for displayingcontinuously scanned information. When transducers 150, I60 and 170 areconnected to the scan converters 40 or 50 in asynchronous mode thehorizontal and vertical sync pulses from generator 74 are employed toprovide synchronous readout therefrom.

Thus, it is seen that in a conventional type display, the binary codedinformation in the computer is normally directly converted into eitherstroke or video raster information and applied to a monitor. As such,the only video displays possible from any storage or regenerating meansmust come from the computer. In the present invention, however, it isseen that the binary coded information is converted first into a strokeimage and then by using the scan converter, it is converted into rasterinformation. As stated above, these scan converters are read out insynchronism with the sync pulses on the cyclic storage means such asdisk 72. Thus, it is seen that by utilizing this double transformationof the image, it is possible and easily adaptable to include in thesystem virtually any asynchronous display source by applying it to theinput of the scan converter. Furthermore, synchronous raster informationcan be applied directly to the channel selectors and this imageinformation can come also from virtually any source of rasterinformation. It w-ill be understood, of course, that this noncodedraster information can be analog in form similar to a conventionaltelevision signal and also can be digital display information where onlyon and off information on the electron beam provides the display.Furthermore, it will be understood that this noncoded information couldbe applied to a carrier such as by frequency modulating the carrier in aconventional manner. In such a case, demodulators would be present inthe distribution system 80.

It will be noted that a single record and read head is employed for eachtrack-so that during recording the information will continue to besupplied to the monitor connected to that particular channel.

As stated above, vertical and horizontal sync pulses are applied eitherto a single track or two tracks on the disk 72. Normally, coded signalsfor a single binary coded display message or pattern are applied to thegraphic generator and the resulting XYZ signals are applied to a scanconverter, so that a single frame will be read out from the scanconverter through the channel selector 60 onto the disk 72 when actuatedby the vertical and horizontal sync pulses from track TRC. Asynchronoussources are normally applied to a scan converter for conversion to asynchronous output and to accommodate differing resolutions, field sizesand types of scan. They may then be applied through track selector 60for direct recording on the disk. In this case, either the vertical syncpulses or a single home pulse on disk 72 can be applied to gate theseinputs so that signals corresponding to only a single frame will berecorded on the tracks 71 through 71N.

An additional feature is that by regenerating the raster information ondisk 72 in the form described above, relatively inexpensive televisionmonitors can be employed, resulting in a relatively large cost savingwhen a number of output channels or stations are in the system.

The XY locator 110 provides two digital output signals which representthe XY position of a pointer 113 on a tablet 114. Various conventionalmeans can be employed to produce the desired XY signals. Such an exampleis illustrated in US. Pat. No. 3,399,401 in which a tablet is employedwhich does not overlay the display but rather is below or to one side ofthe display. In such a case, coordinates on the tablet 114 correspond tocoordinates on the display. The details of such a system will not beshown, but for purposes of illustration, a converter 111 is shown todevelop digital Y coordinate signals from the pointer 113 and converter112 is shown to illustrate developing digital X coordinate signals fromthe signals from the pointer 113 and the tablet 114. Any suitable systemwhich would so produce binary or digital X or Y coordinate signals inresponse to positioning of pointer 113 can be employed.

In the system shown in US. Pat. No. 3,399,401, the tablet is nottransparent and thence cannot overlay the display. If it is desired tohave a system wherein the identifying area overlays the display, suchsystems as illustrated in US. Pat. No. 2,338,949; 3,527,835 and2,241,544 can be employed. These systems in general utilize two pairs ofplates in the X and Y direction across which an AC signal is employed. Apointer is employed on the display, and the resulting AC output signalsfrom the system which varies as the pointer is moved, can be rectifiedand converted to an analog signal which subsequently can be converted todigital signals to provide XY digital coordinate signals. This XYdigital informationvfrom locator 110 is selectively applied to acoordinate compare 140. The other input to i the compare 140 selectivelyis the XY generator 30.

Thus, the operator can regenerate the information in the graphicgenerator 30, and compare it with the point selected by pointer 113 inthe coordinate compare 140. When coincidences of the X and Y signalsoccur simultaneously, an output is provided which, by way of propertiming or clocking, identifies this point within the subsystem control20.

More specifically, when the difference or distance, between the XYposition signals from graphic generator 30 and the corresponding X 0 Ysignals from pointer 113 are within a selected range, coincidence isrecognized. A means is provided either in the unit or unit to indicatethe range of coincidence. This comparison can either be done in ananalog form or digital form. As a particular example, if the comparison,in fact, is done digitally in the compare unit 140, the X Y signals frompointer 113 (if not in digital form originally) would be passed throughanalog to digital converters, the output being the contents of oneregister containing the X position and one register containing the Yposition. Likewise, the X and Y information from generator would bepassed through 5 analog to digital converters to provide at the outputthereof an X position and a Y position. TI-Ie contents of theseconverters, of course, would be dynamic and change as the output ofgenerator 30 changes. When the magnitude of the difference between X andX and between Y and Y is less than a value established by coded limitsfrom the digital storage and processor 10, a coincidence true conditionis established. When coincidence is detected, either the positionregisters from graphic generator 30 could be stopped or the binary codeddisplay information to the graphic generator could be interpreted so asto locate the position of the particular code or step within the streamof data and orders which initiated the X, Y position placement.Additionally, the X, Y coordinate position at coincidence could beobtained from XY registers of 30.

The multiplex means 130 is employed to selectively apply the signalsfrom pencils such as 110 at a plurality of display stations, to thecoordinate compare circuit 140.

FIGS. 3 and 4 illustrate a method of comparing the coordinatesidentified by the pointer 113 and the output of the graphic generator30. In FIGS. 3 and 4, the computer is adjusted so as to determine if astroke from a graphic generator goes through the window W shown indotted lines in FIG. 3. To this end the signals from the pointer 113 andtablet 114 are passed through converters 111 and 112 to provide binarysignals representing X and Y the position of pointer 113. Alternatively,pens, pointers, or teaching devices with direct digital output may beused. The digital processor provides a selected window by providingarithmetic unit 141 with, as shown, -AX+AX, AY and +AY. The -AX is addedto the X to provide an X coordinate output as shown in FIG. 3. The +AXis added to the X to provide a binary X output. The AY is added to the Yto provide a Y binary coordinate output. The +AY is added to the Y toprovide a Y output. These coordinates are representative of theboundaries of the window W as shown in FIG. 3, as illustrated therein indotted lines. The X deflection applied to deflection coils 42, duringcompare, is applied to an A to D converter 144 which provides a binaryindication of the horizontal coordinate of the electron beam inconverter 40. X X and the output of A to D converter 144 are applied toan arithmetic unit 142. This unit has a one output when X is larger thanX and smaller than X The output of this unit is then applied'to AND gate146.

Point D is connected to A to D converter 145 so that Y deflectioncurrent applied to coils 43 of converter 40 provides a binary indicationof the vertical deflection of the electron beam in converter 40. The Y Youtputs of unit 141 are applied to an arithmetic unit 143. Likewise, theoutput of A to D converter 145 shown as Y is applied to unit 143. When Yis larger than Y,, but smaller than Y there will be one output from 143.

A variation of the preferred method is to convert X,,, X Y,,, and Y toanalog voltages by using digital to analog converters after thearithmetic function 141, while eliminating analog to digital converters144 and 145. In this case, the compare functions 142 and 143 areaccomplished with analog threshold circuits. As used in a binary mode sothat the beam is either off or on, the output of Z amplifier 36 is alsoapplied to AND gate 146. Thus, if units 142 and 143 have a one output,the deflection currents have directed the beam within the window W. Whenthe beam is on so that the Z input to 146 is also a one, the intensifiedbeam is passing through the window W. It will be understood that thiswindow W can be altered in many ways to provide various functions. Ifshown as a square, it allows a predetermined tolerance to identify aposition of the beam. It could, for example, however, by a horizontalline, by making 'A+Y and +AY both zero. Thus, the pointer l 13 and thebeam could be moved up and down to effect a bountary indicator or aheight comparator.

When used as a window to provide tolerance in selecting a beam trace,the output of the AND gate 146, as stated above, will be a one when thebeam passes through the window W. This output could, for example, stopthe reading out of the display information from one of the locations 11through 13 to thereby identify within the computer exactly the programstep which corresponds to where the pointer 113 is pointed. Thusly, thisidentifies in the storage location within the computer, the area ofinterest without requiring any work done by or programming of thecomputer. Alternatively, a counter in the subsystem control could beemployed to count the output words by bytes of the selected displaylocation 11 through 13. When an output occurs from AnD gate 46, thisoutput would stop this counter which would identify the byte or bitwithin the storage locations 11 through 13 that the pointer 113 hasidentified. It will be understood that the multiplex means 130 has notbeen shown in FIG. 4 for purposes of clarity. This, however,'would belocated between the locator 110 or other digital coordinate indicationsignal lines and the arithmetic unit 141 solely for switching purposes.

In addition to the other features, two channels can be connected fromthe output of the distributon network 80 to compare these channels in araster compare unit 120. The compare unit 120 will compare the signalsof the two channels in analog or digital form and by conventional logicwill provide an output signal defining the presence and/or magnitude ofany difference between the signals.

The subsystem control 20 can be actuated by the station keyboard 100 orprocessor so as to actuate and control various positions of the systemillustrated in FIG. 1. For example, this control system is connected tographic generator 30 so as to command the generator to producealphanumeric symbols as well as to produce displays from data inlocations ll, 12 or 13 by reading out from processor into generator 30and then to a scan converter 40 or 50. Furthermore, the control isconnected to scanner I50 and photographic file 151 to select apredetermined image on the film 151. Likewise, the subsystem control isconnected to tape recorder I60, and television camera 170 to therebyselect images from either of these sources. The image selected from 150,160, 170 can be, as stated above, synchronous or asynchronous. Otherportions of the system controlled by the subsystem control 20 viacommands of the keyboard 100 are the switches S1 and S2 to select scanconverter 40 and 50, the channel selector 60 to determine the channelselection, the coordinate compare 140 to effect coordinate compare, andraster compare 120. In providing coordinate compare,

it will be understood that normally the pointer 113 will be manuallypositioned at the desired point and then the selected coded display fromlocations 11, 12, and 13 will be fed into the graphic generator 30.

OPERATION OF THE INVENTION When the operator at the remote station Sdesires a particular display, he actuates ths subsystem control 20 byway ofa keyboard 100 which thereby selects an out- 2, switches 46a and46b are up (and closed) applying deflection signals from the graphicgenerator 30 to the pairs of deflection coils 42 and 43. The amplifier36 is 7 connected to the control grid 41 of the scan converter,

which in the preferred embodiment is a conventional vidicon tube 40operating in darkness. The Z information from 36 being applied to grid41, gates on and off the electron beam from cathode 47-. It will beunderstood that the Z informationcould be applied so as to gate thecathode 47 directly without being applied to the control grid 41. Duringreadout, the electron beam emanating from the cathode 47 of the scanconverter vidicon tube, sweeps the target 44 in the conventional rastermode (as done with a conventional television pickup). This provides aconventional television raster signal at the output terminal 45. Duringreadout, switches 46a and 46b are down (and closed) so that thehorizontal and vertical deflection circuits 46 apply con- 'ventionalraster deflection signals to the pairs of deflection coils 42(horizontal deflection) and coils 43 (vertical deflection).

It will be noted that, by utilizing the scan converters in this system,various display sources 150, and can be fed into the scan converteralthough they are asynchronous and may have scans differing from thesystem output standard. The readout of the converter then delays,synchronizes, and insures the correct scanning sequence of the videosignals, since the circuit 46 is driven or synchronized by vertical orhorizontal sync signals from generator 74. Alternately, where feasible,the units 150, 160 and 170 can have their readout synchronously drivendirectly by the sync signals from 74. In such a case, the outputsthereof are applied directly to the distribution means or through trackselector 60 to the disk storage 70.

Commands from keyboard 100 to control 20 may directly or indirectly viacontrol programming select the scan converter (40 or 50) to be utilized.In addition, commands from keyboard 100 to control 20 condition selector60 to selectively apply the output of scan converter 40 (or 50) to oneof the tracks TRl to TRN on disk 72 providing a display for monitor 90.Thus, it is seen that the graphic generator 30 and the scan converter 40and 50 are a means to convert binary coded information from theprocessor'10 into video raster information. This conversion could beachieved by other translation techniques. Such a recording and switching(of unit 60) is set forth in detail in the above copending applicationSer. No. 682,432.

' cessed within processor 10, etc., without disturbing the displayedimage as originally provided by this coded information from 11, 12 or13. This is in contrast to other systems that recirculate the binarycoded information in unit or in an associated buffer memory to producethe display.

1f the operator desires to locate a point on the display, he employs thepointer 113 that develops X Y coordinate signals of a point on thedisplay. This signal is compared with signals being generated from thegraphic generator 30 in the coordinate comparator 140. This enablesidentification of intermediate points within displayed symbols or linesegments not represented by binary coded information in the processor,without complicated processing within unit 10. As set forth above, it isgenerally desirable to identify an area through which a portion of adisplayed construction passes, such as shown in FIG. 3, and identifiedas W. The processor 10 provides digital signals representing thedimensions of this area in AX, +AX, AY and +AY. The pointer 113 providesdigital X and Y information which specifies the position of area W andwhich are added to the AX and AY information to define the sides of thewindow W identified in FIG. 3 as X X Y and Y When a trace of the beam ontarget 44 passes through such a window, there is an output from AND gate146 which then can effect an indication of the position of the penrelative to the displayable information, without the use of translationin the processor 10. THis is made possible by comparing the informationfrom pointer 113 with the stroke information in the generator 30. Asstated above, the window W could be made various sizes of a rectangle oreven a line. Further, when identifying a line element of the display,this window provides a programmable tolerance limit.

While in accordance with the Patent Statutes, we have described what atpresent is considered to be the preferred embodiment of our invention,it will be obvious to those skilled in the art that various changes ormodifications may be made therein without departing from the presentinvention.

We claim: 1. Display system comprising: digital processing meansincluding memory means having binary coded information representative ofa visual display; converter means operative to convert said codedinformation into non-coded television raster information that can beapplied to a television display device for producing a visual displaythereon; cyclic storage means connected to said converter means forcyclically storing said noncoded television raster information, whereinsaid converter means includes generator means for converting said codinginformation to non-coded display information, and scan converter meanssynchronizing said non-coded display information with said cyclicstorage means; television display means; transducer means for manuallyidentifying by XY coordinate signals a portion on said display and meanscomparing the signals of said generator means with the XY coordinatesignals of said transducer means; and 1 connecting means for selectivelyconnecting said storage means and said display means to regenerate saidnon-coded television raster information and effect a continuousapplication thereof to the visual display on said display means.

2. Display system as set forth in claim 1 wherein said portion of saiddisplay is a rectangle determined by a pointer and preselected codedboundary signals in said digital processing means.

3. Display apparatus as set forth in claim 1 wherein said memory meansincludes a plurality of discrete binary information representative of aplurality of visual displays,

wherein said cyclic storage means stores and cyclically regenerates aplurality of noncoded information, and

means comparing the raster of one display with the raster of anotherdisplay.

4. A display system for digital and analog information, said systemcomprising a digital processor having a plurality of storage locationstherein, each of said storage locations having binary coded informationrepresentative of a discrete image;

a graphic generator coupled to said digital processor for transducingthe binary coded information into X, Y, Z signals capable of deflectingan electron beam;

scan converter means coupled to said graphic generator for convertingthe X, Y, Z signals into television type raster information of an analogor digital nature;

track selector means connected to the output of said scan convertermeans;

magnetic storage means connected to the output of said track selectormeans, said magnetic storage means having a plurality of endless tracksformed thereon for storing and cyclically regenerating rasterinformation received from said scan converter means;

a distribution network connected to an output of said magnetic storagemeans;

and a plurality of television monitors coupled to said distributionnetwork for displaying the discrete image stored in said digitalprocessor.

5. The display system of claim 4 wherein at least one source of beamdirecting and intensification or video information is coupled to theinput of the scan converter means; and

a selection of alternate video sources including a video tape recorder,television camera, and film scanner are also provided, said sourcesbeing coupled directly to the distribution network.

1. Display system comprising: digital processing means including memorymeans having binary coded information representative of a visualdisplay; converTer means operative to convert said coded informationinto non-coded television raster information that can be applied to atelevision display device for producing a visual display thereon; cyclicstorage means connected to said converter means for cyclically storingsaid noncoded television raster information, wherein said convertermeans includes generator means for converting said coding information tonon-coded display information, and scan converter means synchronizingsaid noncoded display information with said cyclic storage means;television display means; transducer means for manually identifying byXY coordinate signals a portion on said display and means comparing thesignals of said generator means with the XY coordinate signals of saidtransducer means; and connecting means for selectively connecting saidstorage means and said display means to regenerate said non-codedtelevision raster information and effect a continuous applicationthereof to the visual display on said display means.
 2. Display systemas set forth in claim 1 wherein said portion of said display is arectangle determined by a pointer and preselected coded boundary signalsin said digital processing means.
 3. Display apparatus as set forth inclaim 1 wherein said memory means includes a plurality of discretebinary information representative of a plurality of visual displays,wherein said cyclic storage means stores and cyclically regenerates aplurality of noncoded information, and means comparing the raster of onedisplay with the raster of another display.
 4. A display system fordigital and analog information, said system comprising a digitalprocessor having a plurality of storage locations therein, each of saidstorage locations having binary coded information representative of adiscrete image; a graphic generator coupled to said digital processorfor transducing the binary coded information into X, Y, Z signalscapable of deflecting an electron beam; scan converter means coupled tosaid graphic generator for converting the X, Y, Z signals intotelevision type raster information of an analog or digital nature; trackselector means connected to the output of said scan converter means;magnetic storage means connected to the output of said track selectormeans, said magnetic storage means having a plurality of endless tracksformed thereon for storing and cyclically regenerating rasterinformation received from said scan converter means; a distributionnetwork connected to an output of said magnetic storage means; and aplurality of television monitors coupled to said distribution networkfor displaying the discrete image stored in said digital processor. 5.The display system of claim 4 wherein at least one source of beamdirecting and intensification or video information is coupled to theinput of the scan converter means; and a selection of alternate videosources including a video tape recorder, television camera, and filmscanner are also provided, said sources being coupled directly to thedistribution network.